Metallica playing a trade show? It's the kind of deliciously strange bit of news a person might share on Facebook - but Salesforce.com would rather see it posted on Chatter.

Salesforce, the San Francisco cloud-computing company, is staging its annual Dreamforce conference from Tuesday to Friday at Moscone Center. The conference will bring together a host of leaders in cloud computing - and, yes, Metallica, playing its first corporate gig ever - to talk about the industry's future. More than 40,000 people have registered to attend.

Salesforce, which has traditionally announced new products and acquisitions at Dreamforce, is expected to make Chatter a focus of the week. The year-old social-networking application for the workplace, which Salesforce started last year, is now being used in 100,000 businesses, according to the company.

It's part of a broader move to bring social-networking features into businesses, an effect boosters call "the social enterprise." And it represents a major part of Salesforce's strategy going forward, executives said.

"Social has changed the way we live our lives today," said Woodson Martin, a senior vice president at Salesforce.

The rise of social networks such as Facebook and Twitter means that customers and employees are interacting constantly online, Martin said. The question is how to use those streams to a business' advantage.

Chatter and products like it allow workers to "follow" one another, collaborate on projects and exchange ideas. The result is a constantly evolving discussion of office life that executives can mine for information about their companies.

Enterprise evolution

The social-networking application marks an evolution in enterprise software, which has lagged behind consumer software in design and user experience. After decades of stagnation, the software is finally approaching parity with consumer tools.

Companies that make it are finding that it's big business. "Software as a service," a technology category that Salesforce helped to create, is now an $89.4 billion industry, according to Gartner Inc. Last week, Palo Alto social business software maker Jive Inc. filed paperwork in anticipation of an initial public offering.

The software has a variety of uses. Redwood Shores' Saba makes software for what founder Bobby Yazdani calls "human capital management" - tools that help companies understand all the key players working for and with them. Auto manufacturers, for example, use it to learn the skills and backgrounds of the various venders that supply parts.

"You have this amazing confluence of events happening that are perfectly timed for an enterprisewide software revolution," said Aaron Levie, founder and CEO of Palo Alto's Box.net, which offers file storage and collaboration services online. "We're talking on the scale of the Declaration of Independence in the enterprise."

Levie said the growth of enterprise software has been driven by three key factors: the maturation of the Web, which has made it far easier to deliver robust services through a browser; the rise of mobile devices, which put new pressure on information technology departments to create experiences on par with executives' smart phones and tablets; and the explosion of social networks.

Better decisions

Companies are learning that there's value to be gained from social networking in the workplace, Levie said.

"Social in the enterprise isn't about virtual crops and throwing sheep at people," he said, referring to games like "FarmVille" that have helped drive Facebook's success. "Social in the enterprise is about getting work done faster, and making better and more intelligent decisions."

David Sacks, CEO of San Francisco social-enterprise company Yammer, said social enterprise is spreading virally to new companies each day.

"We're seeing huge growth in our business," he said. "It's getting easier and easier. People are recognizing the value of it. And also, I think, becoming less fearful of it. I think it's just beginning - but you can start to feel it gaining more acceptance now."

Dream event

Salesforce.com's annual conference runs Tuesday through Friday at Moscone Center in San Francisco. In addition to the company's CEO, Marc Benioff, others who will appear at the event are Facebook Chief Information Officer Tim Campos, Verizon Business President Bob Toohey and Google Chairman Eric Schmidt. Among the performers: Metallica headlines Wednesday's Global Gala, while Thursday's Concert for UCSF Benioff Children's Hospital features Alanis Morissette and Jay Leno.